Appendix I. I

N e w Measurements of Area and Distance for Islands in the Sea of Cor tes

ROBERT W. MURPHY

FRANCISCO S A N C H E Z - P I ~ ~ E R O

GARY A. POLIS

ROLF L . AALBU

Studies of island biogeography frequently attempt to explain the numbers and composition of insular biota (e.g., MacArthur and Wilson 1963, 1967; Lack 1976; Abbott 1983). These investigations involve quantitative, statistical methods using the number of species as the dependent variable. The independent variables used in the correlative regression analyses may include island area (A), distance to nearest source fauna (D), habitat complexity or the number of plant species, elevation, and latitude. The predictive values from such analyses directly depend on the accuracy of the measurements of the independent variables.

Several investigations have examined species numbers on islands in the Sea of CortCs, as summarized in Case and Cody (1983). We measured A and D (to the nearest larger source fauna) for almost 80 islands in the Sea of CortCs clearly discernable from Earth Resources Observation Systems (EROS) satellite photographs. However, many small coastal islands were not measured, such as those at Bahia Coyote in Bahia Concepci6n, as well as all Pacific coast islands. In addition, we could not locate Isla Farallon on any photograph. Some islands that do not remain isolated at low tide, or that cannot be separated on EROS images, have either been combined in the table (e.g., Islas Los Coronados) or not measured for island area using satellite images (e.g., Isla San Luis Gonzaga). Nevertheless, many islands with faunal and floral records have been measured. The list includes islands associated with the peninsula of Baja California, both in the Pacific Ocean and the Gulf of California.

For measurements determined from EROS photographs, the error in repeated, di- rect measurements of D was f0 .2 km. Area, A, determined using a digitizing tablet, varied by less than 3% for the large islands, by about 5% for intermediate sized islands, and by as much as 60% for small islands. Estimates of A for extremely small

448 Appendixes

islands (<0.2 km2) should be considered tentative, unless specifically surveyed. Final estimates of A were determined by comparing digitized island shapes with aerial pho- tographs, particularly those in Miller and Baxter (1977), to determine the best digi- tized replication of island shape, and by comparing relative island size among the smaller-sized islands. For statistical purposes, it should be noted that all measurements were made from the same scale (1 : 121,12 l), and thus all are scaled equally and differ proportionally.

On comparison, we found a surprising lack of correspondence with published val- ues (e.g., Soul6 and Sloan 1966; Case 1975: Gastil et al. 1983). Discrepancies in measurement of A and D between satellite and published measurements for some islands were as large as fourfold, and frequently reached twofold. In general, the new estimates of A were slightly smaller than those previously published. The discrepan- cies in measurements are not attributable to different scale maps, as evidenced by numerous shifts in rank order of size. The discrepancies probably result from the previous estimations of A and D being made from inaccurate navigational maps.

These new measurements may significantly affect the conclusions of previous bio- geographic investigations. For example, Gastil et al. (1983) reported San Ildefonso and San Francisco islands as having equal areas (2.6 km3). Surprisingly, the latter island supports almost three times as many lizard species as the former (Murphy and Ottley 1984), an observation previously attributed to island topography (Murphy 1983). Measurements from EROS satellite photographs, however, resulted in esti- mates of A of 0.6 km2 for San Ildefonso and 1.5 km2 for San Francisco, nearly a threefold difference. Thus, differences in A alone may adequately explain the variation in numbers of lizard species on these two islands as a quantification of habitat avail- able to support stable populations of species; explanations of habitat complexity (Mur- phy 1983) are unnecessary.

Comments on the Table of Data

Completeness

We have attempted to list all islands in the region that have associated biological data. These include islands that have been remeasured, as well as those that have not. Some of the smaller islands could not be located on satellite images or in standard gazetteers. Thus, these islands have no coordinates. The problem is further complicated by the occurrence of numerous synonyms used for the same island. Our list does not include many unnamed rocks (e.g., those charted around Isla San Marcos), or named islets for which there are no biological data. We would appreciate receiving specific island coordinates obtained via Geographic Positioning Systems (GPS), as well as island areas and elevations determined through on-site surveys.

A cursory review of the table (Al.l-1) shows many missing data points. As far as we can determine, no reliable data exist for these missing values.

Island Synonyms

We have attempted to summarize all known synonyms of islands. In summarizing data, we have discovered many errors in attributing species to particular islands. Thus,

Island Measurements 449

our island-name synonyms reflect biological attributes as well as variances in geo- graphic and map names. In table (Al.11, individual islands may still be listed more than once. For example, we give one listing for Isla de Altamura and another for Isla Altamura. The island coordinates indicate that these islands are very close to one another, but the separate listing by the U.S. Board on Geographic Names suggests the occurrence of two nearby islands.

Island Areas

Many islands have no estimated areas. This is particularly true for smaller islands and rocas. However, data are also missing for many larger islands, particularly those associated with the head of the gulf and in Pacific coast lagoons. In general, we have avoided making island area estimations from navigational maps.

Latitude and Longitude Coordinates

The latitude and longitude coordinates of most islands were taken from the U.S. Board on Geographic Names (USBGN). Our on-ground survey found no variance from those posted on the U.S.Geographic Survey web site (www-nmd.usgs.gov/www/gnis/index. html). Apart from these coordinates, the specific locations of islands vary from map to map and may be unreliable to within 5'-10' or more. Most of the previously pub- lished island coordinates appear to have been taken from inaccurate maps, the same maps used to estimate island size and distance. For example, during a trip to the gulf islands in 2000, one of us (R.W.M.) used a Garman GPS3+ to navigate from San Esteban to Angel de la Guarda in fog. This GPS unit, which shows maps, indicated that we were 3.5 km east of the island in the gulf when we were standing on Angel de la Guarda. In our table of data, we unfortunately found it necessary to use some previously published coordinates due to the absence of more recently gathered data. Coordinates given to seconds were taken from the USBGN database, and these appear to be very accurate. Locations given in degrees and minutes were estimated from various maps or taken from the literature, and these are likely to be inaccurate to varying degrees. Among USBGN coordinates, some variation occurs. For example, the coordinates for lsla Salvatierra are listed as 30°03'00" N, 114"29'00" W, whereas the synonym Isla Lobos is listed as 30°03'00" N, 114°31'00" W.

Distance to Nearest Faunal or Floral Source

Estimates of distance for the major islands in the gulf are measured from EROS satellite images and are indicated as such in the table of data. Some estimates of distance have been taken from other published sources, and we caution against using these as accurate measures.

Elevations

Considerable variation occurs in published estimates of island elevations. We have made few direct measurements on our own, but rather repeated commonly published data.

450 Appendixes

Ocean Depths

Navigational charts differ considerably in ocean depth profiles. For studies of island biogeography, the most critical issues are (1) were the islands connected to the penin- sula during the last (or older) glacial event, and (2) what is the sequence of isolation for landbridge islands? Isla Carmen has been listed as being both a deep-water island and a landbridge island, depending on which map is used to determine ocean depths. DNA sequence data suggest that Carmen is likely a deep-water island (chap. 8).

References

Abbott, I. 1983. The meaning of z in specieslarea regressions and the study of species turnover in island biogeography. Oikos 41:385-390.

Case, T.J. 1975. Species numbers, density compensation, and colonizing ability of lizards on islands in the Gulf of California. Ecology 56:3-18.

Case, T.J., and M.L. Cody. 1983. Island Biogeography in the Sea of Cortkz. University of California Press, Berkeley.

Gastil, R.G.; J. Minch, and R.P. Phillips. 1983. The geology and ages of islands. In: T.J. Case and M.L. Cody (eds), Island Biogeography in the Sea of Cortkz. University of California Press, Berkeley, CA; pp. 13-25.

Lack, D. 1976. Island Biology Illustrated by the Land Birds of Jamaica. University of Califor- nia Press, Berkeley.

Lewis, L., and P. Ebling. 1971. Baja Sea Guide. Miller Freeman Publications, San Francisco, CA.

MacArthur, R.H., and E.O. Wilson. 1963. An equilibrium theory of insular zoogeography. Evolution 17:373-387.

MacArthur, R.H., and E.O. Wilson. 1967. The Theoly of Island Biogeography. Princeton Uni- versity Press, Princeton, NJ.

Miller T., and E. Baxter. 1977. The Baja Book II. Baja Trail Publications, Huntington Beach, C A.

Murphy, R.W. 1983. The reptiles: origins and evolution. In: T.J. Case and M.L. Cody (eds), Island Biogeography in the Sea of Cortkz. University of California Press, Berkeley, CA; pp. 130-158.

Murphy, R.W.; and J. R. Ottley. 1984. Distribution of amphibians and reptiles on Islands in the Gulf of California. Annals of Carnegie Museum 53:207-230.

SoulC, M., and A.J. Sloan. 1966. Biogeography and distribution of the reptiles and amphibians on islands in the Gulf of California, Mexico. Transactions of the Sun Diego Society of Natural Histoly 14: 137-156.

Tab

le I

. I - I

Isla

nd m

easu

rem

ents

Oce

an

Stat

e or

A

rea

Dis

tanc

e E

leva

tion

Dep

th

Reg

ion

Isla

nd G

roup

(k

m3)

L

atitu

de

Lon

gitu

de

(km

) D

Mea

sure

d to

(m

) (m

) N

ame

Pac

ific

Isl

ands

A

baro

a B

CS

Ade

laid

a (E

lide)

B

CN

A

dent

ro (

El

Zap

ato,

Inn

er I

slet

) PO

A

fuer

a (E

l T

oro,

out

er i

slet

; Is

la

PO

E

xtar

ior)

A

lam

bre,

El

(Isl

ote

El

Ala

rnbr

e)

BC

S

Lag

una

San

Igna

cio

Ros

arito

G

uada

lupe

14

.58

Gua

ddup

e 15

.62

Peni

nsul

a 12

" G

uada

lupe

22

7 G

uada

lupe

20

6

Lag

una

Ojo

de

Lie

bre

Lag

una

San

Igna

cio

Bah

ia A

sunc

ion

Ced

ros

348

Ced

ros

Ced

ros

Ced

ros

Ced

ros

Ced

ros

Ced

ros

Are

na (

Ana

) A

sunc

ion

(Ang

ulo

Roc

k)

Ced

ros

(Cer

ros)

C

edro

s is

let

A

Ced

ros

isle

t B

C

edro

s is

let

C

Ced

ros

isle

t D

C

edro

s is

let

E

Ced

ros

isle

t F

C

hest

er i

slet

s (C

hest

er r

ocks

) C

hoyi

ta (

Islo

te L

a C

hoyi

ta)

BC

S B

CS

BC

N

BC

S

BC

S B

CS

BC

S B

CS

BC

S B

CS

BC

S

Peni

nsul

a 50

Pe

nins

ula

1204

" C

edro

s C

edro

s C

edro

s C

edro

s C

edro

s C

edro

s Pe

nins

ula

Punt

a E

ugen

ia

Lag

una

Ojo

de

Lie

bre

Rev

illag

iged

o C

lari

dn (

Sant

a R

osa:

San

Bar

- PO

to

lom

C)

La

Con

cha

BC

S

Mex

ico

Lag

una

Ojo

de

Lie

bre

Cor

onad

o is

let

(Roc

a M

edio

) B

CN

C

oron

ado

del

Cen

tro

(del

B

CN

M

edio

) C

oron

ado

del

Nor

te

BC

N

Cor

onad

o de

l Su

r B

CN

Los

Cor

onad

os

Los

Cor

onad

os

1 Pe

nins

ula

Los

Cor

onad

os

1 2.5

tota

l L

os C

oron

ados

14

2"

205"

(c

ontin

ued)

Tabl

e I.

I -I

(Con

tinu

ed)

Oce

an

Stat

e or

A

rea

Dis

tanc

e E

leva

tion

Dep

th

Nam

e R

egio

n Is

land

Gro

up

(km

') L

atit

ude

Lon

gitu

de

(km

) D

Mea

sure

d to

(m

) (m

)

Cre

scie

nte

(Cra

cien

te)

Gar

zas

Gua

dalu

pe

La

Islit

a L

os M

orro

s M

agda

lena

(Sa

nta

Mag

dale

na)

Man

grov

e M

orro

Her

mos

o N

ativ

idad

N

ativ

idad

Nor

th r

ock

Nat

ivid

ad-R

oca

Vel

a (S

ail

Roc

k)

Neg

ro

Nor

th R

ock

Pelic

anos

L

a Pi

edra

Pied

ra d

e Sa

n Jo

sC

Pied

ra N

egra

(Is

lote

Pie

dra

Neg

ra)

Pir

imid

e R

ocas

Alij

os (

x3)

Roc

a de

Cue

rvo

Roc

a D

oble

Pin

Lul

o R

oca

Ele

fant

e (E

lefa

nte)

R

oca

Mon

umen

t0

Roc

a O

'Nea

l R

oca

Part

ida

Roc

a P

inic

ulo

-

BC

S B

CS

PO

BC

N

BC

S B

CS

BC

S B

CS

BC

S B

CS

BC

S

PO

PO

BC

S B

CS

BC

N

BC

S

Mag

dele

na

Lag

una

San

Igna

cio

Gua

dalu

pe

Gue

rrer

o N

egro

B

ahia

Tor

tuga

s B

ahia

Mag

dale

na

Bah

ia M

agda

lena

T

ortu

gas

Nat

ivid

ad

Nat

ivid

ad

Nat

ivid

ad

Gua

dalu

pe

Rev

illag

iged

o L

agun

a Sa

n Ig

naci

o L

agun

a O

jo d

e L

iebr

e S

of E

l R

osar

io

Punt

a E

ugen

ia

Rev

illag

iged

o R

evill

agig

edo

Rev

illa

gige

do

Rev

illag

iged

o G

uada

lupe

R

evill

agig

edo

Rev

illag

iged

o R

evil

lagi

gedo

R

evill

agig

edo

<I

Peni

nsul

a (l

ow)

232

Peni

nsul

a 12

98

>365

1 Pe

nins

ula

415

9 15

0"

17"

Peni

nsul

a C

lari

6n

Soco

rro

Gua

dalu

pe

Cla

ri6n

So

corr

o Pe

nins

ula

Soco

rro

Roc

as d

el V

apor

(St

eam

boat

P

O

Roc

k)

Roc

as L

a So

leda

d (P

iedr

a S

anto

B

CN

T

hom

as)

San

Ben

edic

to (

Inoc

ente

s;

PO

A

iiubl

ada)

S

an B

enito

del

Est

e (B

onito

E)

BC

S

Gua

dalu

pe

20°0

6'

San

to T

hom

6s

ca.

31°3

0'

Peni

nsul

a

Rev

illag

iged

o 19

"18'

00"

Peni

nsul

a

San

Ben

itos

1 2X

018'

C

edro

s Pe

nins

ula

San

Ben

itos

1 6.3

tota

l 2X

018'

Sa

n B

enito

s 2X

018'

B

ahia

Ros

ario

0.

4 29

"47'

00"

San

Qui

ntin

2.

3 30

°30'

00"

nr.

Bah

ia A

sunc

ion

27"0

8'

Mag

dele

na

24"2

7'00

"

San

Ben

ito d

el C

entr

o (B

onito

C)

BC

S Sa

n B

enito

del

Oes

te (

Bon

ito W

) B

CS

San

Jer

6nim

o (S

an G

erom

ino)

B

CN

Sa

n M

artin

B

CN

Sa

n R

oque

B

CS

Sant

a M

arga

rita

(M

arga

rita

; B

CS

Sant

a M

agda

lena

) S

anto

Dom

ingo

B

CS

P

V1

Soc

orro

(Is

las

de S

anto

Tom

is)

PO

w

Tod

os S

anto

s (N

) B

CN

Peni

nsul

a Pe

nins

ula

Peni

nsul

a Pe

nins

ula

Mag

dele

na

Rev

illag

iged

o 18

"45'

00"

Bah

ia d

e T

odos

3

1°49

' Sa

ntos

1.

2 to

tal

Bah

ia d

e T

odos

31

°48'

Sa

ntos

L

agun

a O

jo d

e 27

"53'

L

iebr

e

Peni

nsul

a Pe

nins

ula

Tod

os S

anto

s (S

) B

CB

Pe

nins

ula

Zac

atos

o B

CS

Sea

of

Cor

tis

Alc

atra

z A

lcat

raz

Alg

adon

es,

de 1

0s

Alg

adon

es

Alm

agre

Chi

co (

Alm

agre

s C

hi-

quito

) A

lmag

re G

rand

e (A

lmag

res

Gra

nde)

A

ltam

ura.

de

Alta

mur

a

28"4

9'00

" 29

"ll'O

O"

24"5

2'00

" B

ahia

Gua

ymas

27

"45'

00"

Bah

ia G

uaym

as

0.09

8~ 2

7"55

'00n

SO

N

SO

N

SIN

S

ON

S

ON

So

nora

Sono

ra

Bah

ia G

uaym

as

0.2

97

~ 2

7"55

'00"

S

ON

SIN

S

IN

Bah

ia S

anta

Mar

ia

Tac

hich

ilte

Tab

le I

. I -I

(C

onti

nued

)

Oce

an

Stat

e or

A

rea

Dis

tanc

e E

leva

tion

Dep

th

Reg

ion

Isla

nd G

roup

(k

m3)

L

atit

ude

Lon

gitu

de

(km)

D M

easu

red

to

(m)

(m)

Nam

e

Ang

el d

e la

Gua

rda

(Ang

el d

e la

B

CN

G

uard

ia)

Ani

mas

, L

as (

Las

~n

ima

s Su

r)

BC

S A

rbol

eda

SO

N

Ard

illa

SO

N

Ave

J A

L

Bah

ia A

nim

as N

E

BC

N

Ang

el d

e la

Gua

rda

Peni

nsul

a

San

JosC

Sa

n Jo

sC

Bah

ia G

uaym

as

Bah

ia d

e la

s ~

nim

as

B

ahia

de

las

~n

ima

s

Col

orad

o R

iver

E

spir

itu S

anto

Peni

nsul

a

Bah

ia ~

nim

as

SW

B

CN

Pe

nins

ula

R

P

Baj

ito,

El

BC

N

Bal

lena

B

CS

Bar

edito

SI

N

Bar

go (

Bar

ga)

BC

S B

asac

ori

SO

N

Bla

nca

SO

N

Bla

nca

(~n

ima

s Bay

) B

CN

Esp

iritu

San

to

Peni

nsul

a B

ahia

Con

cepc

idn

nr.

Sina

loa

Gua

ymas

B

ahia

de

las

Ani

mas

nr

. D

anza

nte

Sono

ra

Peni

nsul

a

Bla

nco

(Roc

a B

lanc

a, I

slot

e B

CS

Bla

nco)

B

lanc

o (B

lanc

a, C

once

pci6

n)

BC

S B

ledi

tos

SIN

B

ledo

s SI

N

Bot

a B

CN

Peni

nsul

a

Bah

ia C

once

pcid

n nr

. Son

ora

nr.

Sono

ra

Ven

tana

Peni

nsul

a

La

Ven

tana

Pe

nins

ula

La

Ven

tana

Pe

nins

ula

Cab

eza

de C

abal

lo

BC

N

Cab

eza

Cab

eza

de N

ativ

idad

JA

L

Cal

aver

as

BC

N

0.91

d C

oron

ado

1 7b

3.33

d Pe

nins

ula

Can

dele

ro (

Ven

tana

, L

eon

Dor

- S

ON

m

ido)

C

ardo

nes

SIN

C

ardo

nosa

Est

e (C

ardo

nosa

) B

CN

C

arm

en (

El

Car

men

) B

CS

Cay

o B

CS

Bah

ia G

uaym

as

nr.

Maz

atld

n Pa

rtid

a N

. C

arm

en

San

Jos

C

0.64"

artida

N

. 6

.03

~

Peni

nsul

a 47

9"

1.

58

ha

n Jo

sC

7.8a

d Pe

nins

ula

2.85

d Pe

nins

ula

1 2b

0.0

6~

L

a V

enta

na

8.73

d Pe

nins

ula

767"

Cer

raja

B

CN

V

enta

na

Cer

ralv

o B

CS

Cer

ro B

lanc

o B

CS

Cer

ro L

a B

ufad

ora

BC

S C

hape

tona

(R

asa)

S

ON

C

holla

B

CS

Cer

ralv

o C

ape

Reg

ion

Cap

e R

egio

n B

ahia

Gua

yrna

s C

arm

en

13.9

4~

Peni

nsul

a 6"

0

.24

~

Car

men

9.

84d

Cor

onad

os

0.85

D

dtil

100

G

Cho

lludo

(L

obos

, L

a Fo

ca,

Roc

a S

ON

F

oca)

S

of

Tib

urdn

1.09

" T

ibur

dn

Chi

vos

SIN

C

iari

(C

iari

s, S

iari

) S

ON

C

ocin

as (

Col

orad

o)

JAL

D

auto

SI

N

Con

sag

(Roc

a C

onsa

g, R

oca

BC

N

Con

sagr

acio

n)

Cor

m

BC

N

Cor

onad

ito

BC

N

San

Felip

e 30

" Pe

nins

ula

San

Ped

ro M

irti

r C

oron

ado

0. la

d

Cor

onad

o 3

.09

~

Peni

nsul

a 2

.18

~

Peni

nsul

a C

oron

ado

(Sm

ith,

Sm

iths

) B

CN

B

ahia

de

10s

Ang

eles

C

oron

ados

C

oron

ados

(L

os C

oron

ados

) B

CS

2.61

d Pe

nins

ula

283'

35

(c

ontin

ued)

Tab

le I

. I - I

(C

onti

nued

)

Oce

an

Sta

te o

r A

rea

Dis

tanc

e E

leva

tion

Dep

th

Reg

ion

Isla

nd G

roup

(k

m3)

L

atitu

de

Lon

gitu

de

(km

) D

Mea

sure

d to

(m

) (m

) N

ame

Cor

onad

os i

slet

SW

(Sa

ntia

go?)

B

CS

Cor

onad

os

0.7

3~

C

oron

ados

1

.09

~

Peni

nsul

a 1

.15

~

San

JosC

9.2

7"en

insula

0.

746~

Pe

nins

ula

Coy

ote

(El

Part

ido,

El

Coy

ote)

B

CS

San

JosC

Coy

ote

(El

Coy

ote)

B

CS

BC

N

SIN

B

CS

SO

N

BC

S S

ON

Bah

ia C

once

pcid

n Sa

n Pe

dro

MB

rtir

nr.

Maz

atli

n B

ahia

Con

cepc

idn

Cra

veri

es

Cre

stdn

L

a C

ueva

C

ueva

D

anza

nte

P

DB

til (

Cho

lludo

, Tur

ners

; in

o\

Tur

ner;

Tor

nero

) D

ivis

ion

(Nav

io;

de l

a V

ela)

1.6

73

~

Sono

ra

2.61

d Pe

nins

ula

1 .94

d T

ibur

6n

Ang

el d

e la

Gua

rda

0.05

A

ngel

de

la

Gua

rda

BC

N

La

Dob

le (

Alg

odon

es)

Enc

anta

da E

ast

(Bir

d ro

ck)

Enc

anta

da (

som

etim

es r

efer

red

to a

s E

l C

hollu

do:

but

see

abov

e; I

ncan

tada

) E

ncan

tada

Gra

nde

(Sal

vat

ie~

~a

[in

erro

r],

San

Lui

s, S

an L

uis

Gon

zaga

[in

err

or])

de

Enm

edio

(B

lanc

a, P

aste

l)

Esp

iritu

San

to

Est

anqu

e (L

a V

ibor

a, P

ond)

SON

B

CN

B

CN

Alg

odon

es

Enc

anta

das

Enc

anta

da

0.5

5~

E

ncan

tada

6

.~

5~

Peni

nsul

a

BC

N

Enc

anta

das

5.45

' Pe

nins

ula

5.76

d E

ncan

tada

Bah

ia G

uaym

as

Esp

iritu

San

to

Ang

el d

e la

Gua

rda

SON

B

CS

BC

N

6.1

5~

Pe

nins

ula

0.61

d A

ngel

de

la

Gua

rda

El

Fier

ro

Flec

ha

SIN

B

CN

nr

. SO

N

La

Ven

tana

2.

79d

Peni

nsul

a 0.

61d

La

Ven

tana

Las

Gal

eras

E

Las

Gal

eras

W

BC

S B

CS

Mon

serr

ate

Mon

serr

at

2.73

' M

onse

rrat

2.

73'

Mon

serr

at

0.30

' L

as G

aler

as

Eas

t 0.

87~

E

spir

itu S

anto

G

allin

a G

allo

(E

l G

allo

) G

allo

G

arra

pata

G

emel

os E

(G

emel

itos)

BC

S B

CS

BC

S SI

N

BC

N

Esp

iritu

San

to

Bah

ia C

once

pci6

n E

spir

itu S

anto

nr

. So

nora

L

os G

emel

os

0.46

~

Esp

iritu

San

to

0.30

' G

emel

itos

W.

2ob

0.79

' Pe

nins

ula

0.8

5~

Pe

nins

ula

2ob

Gem

elos

W (

Gem

elito

s)

del

Gie

ro

Gor

e (C

ore)

G

rani

to (

Gra

nite

)

BC

N

SIN

B

CN

B

CN

Los

Gem

elos

nr

. So

nora

C

olor

ado

Riv

er

Ang

el d

e la

Gua

rda

1.3

9~

A

ngel

de

la

85"

Gua

rda

24"

Gua

pa (

Gua

po, M

orro

Tec

o-

mat

e)

P

cn

Hab

ana

BC

S B

ahia

Con

cepc

ion

BC

S M

ainl

and

San

Die

go

2.1"

Pe

nins

ula

Her

man

o de

l N

orte

H

erm

ano

del

Sur

Hue

rfan

ito,

El

Hui

vuila

y (H

uivu

lay,

Hui

vula

i, T

6bar

a)

SIN

SI

N

BC

N

SO

N

1 14°

39'0

0"

0.48

' Pe

nins

ula

23"

27'

110"

01'0

0"

Enc

anta

das

107"

38'0

0"

108"

53'0

0"

107"

33'3

0"

105"

55'0

0"

32

Nay

arit

85"

46

Igua

na

El

Indi

o E

l In

fier

nito

Is

abel

(Sa

n Is

abel

a, I

sabe

lla,

Gav

iota

s)

Las

Isl

itas

Isle

t E

of

Part

ida

N

Jalte

mba

SIN

SI

N

SIN

N

AY

nr.

SO

N

Tre

s M

aria

s

BC

S B

CN

JA

L

BC

N

111°

17'

0.5

5~

Pe

nins

ula

18'

113"

Ol'

19.39

"eni

nsul

a 15

" 40

0 10

5"18

'00"

11

3"3 1

' 0.

36'

Flec

ha

25

35

2.12

' Pe

nins

ula

(con

tinue

d)

nr.

Dan

zant

e Pa

rtid

a N

Joro

bado

L

a V

enta

na

Tabl

e I.

I - I

(Con

tinu

ed)

Oce

an

Stat

e or

A

rea

Dis

tanc

e E

leva

tion

Dep

th

Reg

ion

Isla

nd G

roup

(k

m')

Lat

itud

e L

ongi

tude

(k

m)

D M

easu

red

to

(m)

(m)

Nam

e

Lag

arti

ja

BC

N

W o

f Is

. Sa

lsi-

pu

edes

nr

. S

ON

B

ahia

Gua

ymas

B

ahia

Con

cepc

i6n

Ven

tana

0.3

0~

Sa

lsip

uede

s

de la

Lec

hugu

illa

(Lec

hugu

illa)

SI

N

Leo

n (S

anta

Cat

alin

a)

SO

N

La

Lie

bre

BC

S L

lave

B

CN

2

.Ud

Pe

nins

ula

0.0

6~

L

a V

enta

na

La

Lob

era

(Isl

ote

La

Lob

era)

L

ober

a L

obos

R w

L

obos

(A

reo)

L

obos

(G

avio

ta)

Los

Isl

otes

L

uz

Mac

apul

e (d

e M

acap

ule,

Rac

a-

pule

) M

aria

Cle

ofas

M

aria

Mad

re

Mar

ia M

agda

lena

BC

N

SO

N

SIN

S

ON

B

CS

BC

S B

CS

SIN

nr.

Maz

atld

n

La

Paz

Esp

iritu

San

to

Peni

nsul

a Pa

rtid

a Su

r

Sina

loa

Nay

arit

Nay

arit

Nay

arit

Mar

ia C

leof

as

Mar

ia M

adre

Ang

el d

e la

G

uard

a

Gul

f G

ulf

Gul

f

Tre

s M

aria

s T

res

Mar

ias

Tre

s M

anas

Mas

coca

hui

Mej

ia

SIN

? B

CN

nr

. So

nora

A

ngel

de

la G

uard

a

Mel

endr

es

SIN

D

el M

ero

SIN

M

esti

za (

Chu

enqu

e)

BC

S M

iram

ar (

El

Mue

rto,

Lin

k)

BC

N

Mes

tiza

E

ncan

tada

s 0.3

0"en

insula

3.

39d

Peni

nsul

a

Mit

lin

BC

N

0.1

56

~ 2

9"04

' 1 1

3"31

f 0.

12'

Cor

onad

o 2.

00'

Peni

nsul

a L

as M

onas

Nor

te

Las

Mon

as S

ur

NA

Y

NA

Y

BC

S

Isab

ella

Is

abel

la

Mon

serr

at

19

.86

~

25"4

1f00

" 11

1°03

'00"

13

.70'

Pe

nins

ula

Mon

serr

at (

Mon

serr

ate,

Mon

ser-

ra

to,

San

ta C

ruz)

M

onta

pue

(Mon

tagn

e)

Mor

rito

(In

glC

s. B

arra

El

Mor

- ri

to)

Neg

rita

N

ovill

a P

ijar

os

Pij

aros

P

ijar

os

Palm

ito d

el V

erde

Pa

lmito

de

la V

irge

n Pa

rdo

(Roc

a S

ur, L

os C

ande

- P

iil

\O

lero

s Su

r)

Part

ida

bird

roc

k Pa

rtid

a N

(C

ardo

nosa

, Pa

rtid

a)

BC

N

SON

C

olor

ado

Riv

er

Bah

ia G

uaym

as

JAL

JA

L

SO

N

SIN

SI

N

SIN

S

IN

BC

S

0.88

1h

27"5

4'00

" 1 1

0°52

'00"

1.

042~

So

nora

24

"49'

00"

108"

07'0

0"

23"1

5'00

" 10

8"07

'00"

22

"40'

00"

106"

30'0

0"

23"O

O'O

O"

106"

10'0

0"

0.0

38

~ 2

5'44

' 11

1°13

' 0.

48'

Peni

nsul

a

Bah

ia G

uaym

as

nr.

Maz

atli

n nr

. Nay

arit

nr.

Maz

atli

n nr

. D

anza

nte

BC

N

BC

N

Part

ida

N

San

Lor

enzo

Sur

R

asa

Peni

nsul

a A

ngel

de

la

Gua

rda

Part

ida

Part

ida

Sur

Pass

aver

a Pa

ta

SO

N

BC

S JA

L

BC

N

Esp

iritu

San

to

Esp

iritu

San

to

Ven

tana

B

ota

Peni

nsul

a T

ibur

6n

Sono

ra

SO

N

Pato

s Pa

tos

Pel

cino

(=

Pelic

ano?

) E

l Pe

lican

o (A

lcat

raz,

Tas

sne)

Pe

lican

o Pe

lon

SO

N

SO

N

SON

N

AY

Col

orad

o R

iver

B

ahia

Kin

o ls

abel

a S

onor

a

Tab

le 1

. I - I

(C

onti

nued

)

Nam

e

Oce

an

Sta

te o

r A

rea

Dis

tanc

e E

leva

tion

Dep

th

Reg

ion

Isla

nd G

roup

(k

m3)

L

atitu

de

Lon

gitu

de

(km

) D

Mea

sure

d to

(m

) (m

)

Las

Pel

onas

la

Pef

ia

Peru

ano

(Per

uano

Bla

nca)

Pe

scad

or (

El

Pesc

ador

) de

Pie

dra

de l

as P

iedr

as

El

Pioj

o (P

iojo

)

La

Pita

haya

(Pi

taha

ya,

Sin

Nom

bre)

Pi

taha

ya

Pita

yosa

L

a Po

ma

(Por

no, E

ncan

tada

, C

anta

da)

Que

vedo

E

l R

acito

(Is

lote

El

Rac

ito)

Ram

on

Ran

cho

Ras

a bi

rd r

ock

Ras

ita

Ras

a (R

aza,

La

Ras

a, L

a R

aza)

Ras

e (R

aze,

Raz

a)

de R

edo

Req

ueso

n (E

l R

eque

s6n)

de

la

Ris

ci6n

SIN

N

AY

S

ON

B

CN

S

IN

SIN

B

CN

BC

S

SO

N

SO

N

BC

N

SIN

B

CS

BC

S S

IN

BC

N

BC

N

SO

N

SIN

B

CS

SIN

Bah

ia P

esca

dor

Maz

atli

n

Pioj

o

Bah

ia C

once

pci6

n

Bah

ia G

uaym

as

Enc

anta

das

Bah

ia C

once

pci6

n nr

. So

nora

S

an L

oren

zo S

ur

Mid

riff

Bah

ia C

once

pci6

n

Sono

ra

Peni

nsul

a

Cor

onad

o Pe

nins

ula

La

Ven

tana

Sono

ra

Sono

ra

Enc

anta

da

Gra

nde

Peni

nsul

a S

dsip

uede

s P

anid

a N

. So

nora

Peni

nsul

a

35

35

18' 5' 46' 9'

400 <2"

(con

tinu

ed)

Roc

a be

twee

n Pa

rtid

a N

and

A

ngel

de

la G

uard

a 0.

61d

Pari

da N

10.7

9~

Ang

el d

e la

G

uard

a 1

9.5

8~

Pe

nins

ula

1.2

Div

isio

n A

ngel

de

la G

uard

a Is

abel

la

San

Mar

cos

Sant

a C

atal

ina

San

Jost

.

Roc

a B

lanc

a (P

iedr

a B

lanc

a)

Roc

a G

onlo

ndri

nas

Roc

a L

obos

(Sa

n R

afae

l)

Roc

a M

oren

a (M

oren

a)

BC

N

NA

Y

BC

S B

CS

BC

S N

AY

B

CN

Roc

a N

egra

R

oca

Neg

ra

Roc

a R

asa

Ras

a 1

.58

~

Ras

a 23

" 4 6

' 19

.82~

Pe

nins

ula

400

2.0

Peni

nsul

a 8"

18

' 0.

3 Pe

nins

ula

35"

18'

0.3

6~

A

ngel

de

la

51"

4 6'

Gua

rda

Roc

a Sa

n M

arci

a1

Roc

a So

litar

ia

Roc

a V

ela

(nr.

Mej

ia)

BC

S B

CS

BC

N

S. o

f M

onse

rrat

S.

of

Mon

serr

at

Ang

el d

e la

Gua

rda

Roc

allo

sa

Salia

ca

Sals

ipue

des

(Sal

Si

Pued

es)

BC

N

SIN

B

CN

Sa

n L

oren

zo S

ur

1.5

2~

Sa

n L

oren

zo

114'

40

0 N

orte

19

.21"e

nins

ula

3.39

d Pe

nins

ula

169"

37

' Sa

lvat

ierr

a (C

olor

adito

, L

obos

. L

os L

obos

) B

CN

E

ncan

tada

s

5.21

d M

iram

ar

2.97

d E

ncan

tada

Sa

n A

ndre

s Sa

n A

rem

ar

JAL

B

CN

1.2

1-a

Ven

tana

3.

27d

Peni

nsul

a V

enta

na

San

Aug

ustin

S

an B

asili

o (x

3) (

Roc

as d

e la

G

avio

ta)

San

Cos

me

(Roc

a Sa

n C

osm

e)

JAL

B

CS

BC

S Pe

nins

ula-

M

onse

rrat

1

.45

~

Peni

nsul

a

Tab

le I

. I -

I (C

onti

nued

)

Nam

e

Oce

an

Stat

e or

A

rea

Dis

tanc

e E

leva

tion

Dep

th

Reg

ion

Isla

nd G

roup

(b

3)

Lat

itude

L

ongi

tude

(k

m)

D M

easu

red

to

(m)

(m)

San

Dam

ian

San

Die

go

San

Est

eban

San

Fran

cisc

o

San

Igna

cio

Fara

ll6n

(Far

allo

n de

San

Ign

acio

, Sa

n Y

gnac

io

Fara

llon)

Sa

n Ig

naci

o (d

e Sa

n Y

gnac

io)

San

Ilde

fons

o Sa

n Jo

rge

(Geo

rge)

Sa

n Jo

rge

isle

t-N

Sa

n Jo

rge

isle

t-S

San

JosC

S

an J

uan

Nep

omuc

eno

(San

Ju

an N

epom

uzen

o, n

ow a

pe

nins

ula)

Sa

n Ju

anito

San

Lor

enzo

Nor

te (

Las

~n

ima

s

N,

Ani

ma.

Roc

a B

lanc

a)

San

Lor

enzo

Sur

(Sa

n L

oren

zo)

San

Lor

enzo

(L

a Pa

z)

San

Lui

s (A

lgod

ones

)

BC

S

BC

S

BC

N

BC

S

SIN

SIN

B

CS

SO

N

SO

N

SO

N

BC

S B

CS

Gul

f

BC

N

BC

N

BC

S S

ON

nr.

Mon

serr

at

San

JosC

Mid

riff

San

JosC

San

Ild

efon

so

Bah

ia S

an J

orge

B

ahia

San

Jor

ge

Bah

ia S

an J

orge

Sa

n Jo

sC

La

Paz

Tre

s M

aria

s

San

Lor

enzo

San

Lor

enzo

E

spir

itu S

anto

L

os A

lgod

ones

Peni

nsul

a Sa

n C

osm

e Sa

nta

Cru

z Sa

n Jo

sC

Peni

nsul

a T

ibur

dn

San

Lor

enzo

Su

r Sa

n Jo

sC

Peni

nsul

a Si

nalo

a

Peni

nsul

a So

nora

So

nora

So

nora

Pe

nins

ula

Peni

nsul

a

Nay

arit

Mar

ia M

adre

Sa

n L

oren

zo

Sur

Peni

nsul

a

San

Lui

s G

onza

ga (

Isla

Will

ard)

B

CN

B

ahia

San

Lui

s G

onza

ga

San

Mar

cos

Bah

ia G

uaym

as

1.68

7 29

"48'

00"

114"

23'0

0"

0.00

3 Pe

nins

ula

30.0

7"7~

13'00

" 11

2"06

'00"

4.

91d

Peni

nsul

a 0.

019'

27

'56'

1 1

0°03

' 0.

5 10

' M

ainl

and

San

Mar

cos

BC

S Sa

n N

icol

as

SO

N

San

Pedr

o JA

L

San

Pedr

o M

Brti

r B

CN

Sa

n Pe

dro

MB

rtir

Sono

ra

San

Est

eban

L

obos

S

onor

a S

onor

a Sa

n Pe

dro

Nol

asco

S

ON

Sa

n R

amon

S

ON

Sa

n V

icen

te

SO

N

San

Vin

cent

e S

ON

Sa

nta

Cat

alin

a (C

atld

n, C

atal

ana,

B

CS

Cat

alan

o)

Sant

a C

NZ

B

CS

nr.

Gua

ymas

Bah

ia G

uaym

as

Sant

a C

atal

ina

Son

ora

Peni

nsul

a M

onse

rrat

Pe

nins

ula

San

JosC

Pe

nins

ula

Sant

a C

ruz

Sant

a ln

es (

Sant

a 1n

Cz)

Sa

nta

Mar

ia

BC

S SI

N

BC

N

SIN

SI

N

Sant

a In

es

Satis

pac

Sier

ra E

l N

egro

T

achi

chilt

e (d

e T

achi

chilt

e,

Tal

chic

hilte

, T

achi

chite

, T

achi

chilt

ic)

Tes

obid

re

Tec

uaca

hui

(A T

unos

a)

Tib

ur6n

(de

l T

ibur

6n)

Tije

ras

(Las

Tije

ras,

Roc

a M

edio

) T

imba

bich

i bi

rd r

ock

Tio

Ram

6n

T6b

ari

nr.

Sono

ra

Bah

ia S

anta

Mar

ia

25"3

0'00

" 10

E05

1'00

" 24

"59'

00"

108"

04'0

0"

3 Si

nalo

a

25"2

9'00

" 10

8"49

'00"

25

"35'

00"

109"

01'0

0"

1223

.53~

29

"OO

'OO

" 1 1

2"25

'00"

1

.70

~

Son

ora

0.02

5'

2504

4'33

"~

11 1°

13'3

1"'

1 .M

d Pe

nins

ula

SIN

SI

N

SO

N

BC

S T

ibur

6n

nr.

Dan

zant

e

Esp

iritu

San

to

Bah

ia G

uaym

as

BC

S S

ON

S

ON

(c

ontin

ued)

Tab

le I

. I - I

(Con

tinu

ed)

Oce

an

Sta

te o

r A

rea

Dis

tanc

e E

leva

tion

Dep

th

Nam

e R

egio

n Is

land

Gro

up

(km

3)

Lat

itude

L

ongi

tude

(k

m)

D M

easu

red

to

(m)

(m)

Tor

tuga

(de

Tor

tuga

) B

CS

Tos

acah

ui

SIN

T

res

Mar

ias

isle

t A

G

ulf

Tre

s M

arie

tas

(Las

Tre

s N

AY

M

arie

tas)

L

as T

unas

S

IN

Tun

osa

SIN

V

enad

o (L

a V

enad

o, A

lgod

ones

) S

ON

V

enad

os

SIN

L

a V

enta

na (

Ven

tana

) B

CN

de

las

Vie

jas

SO

N

Vin

oram

a S

IN

Tor

tuga

1

27"2

6'00

f'

Sina

loa

25"3

7'00

" T

res

Mar

ias

Puer

to V

alla

rta

20°4

3'

24"5

1'00

"

Alg

odon

es

0.23

5 27

"57'

00"

La

Ven

tana

1.

41d

28"5

9'00

" 26

"42'

00"

25"2

2'O

Of'

1 11 0

52'0

0"

36.3

0~

Peni

nsul

a 30

9'

1200

26

.65d

S

an M

arco

s 10

9"01

'00"

105"

35'

108"

05'0

0"

11 1°

07'0

0"

0.1

75

Sono

ra

25

113"

30'0

0"

3.1

5~

Pe

nins

ula

120

35

109"

3 1'00

" 10

8"46

'00"

Abb

revi

atio

ns f

or s

tate

or

regi

on:

BC

N,

Est

ado

de B

aja

Cal

ifor

nia

(nor

ther

n st

ate)

; B

CS.

Baj

a C

alif

orni

a Su

r; I

AL

, lal

isco

; N

AY

, N

ayar

it; P

O,

Paci

fic

Oce

an;

SIN

, Sin

aloa

, S

ON

, Son

ora

'Dat

a fr

om L

ewis

and

Ebl

ing

(197

1).

bMea

sure

d by

isl

and

surv

ey.

'Dat

a fr

om S

ea o

f C

orte

z C

hart

s (1

998)

. Fi

sh n

Map

Co.

(A

rvad

a, C

olor

ado)

. d

~e

asu

red

fr

om E

RO

S sa

telli

te p

hoto

grap

hs.

'Dat

a fr

om S

oult

and

Slo

an (

1966

).